Apple Is No. 2

With recent quarterly earnings clocking in at a record $7.3 billion on nearly $28.6 billion in revenue (another record), Apple (NAS: AAPL) is doing rather well. With 20 million iPhones sold in the quarter, up 142% over year-ago levels, along with 9 million iPads (up 183%), the company seems like it's on top of the world. But it's not -- quite.

Sure, it may have temporarily passed up ExxonMobil in terms of market cap earlier today. But when it comes to IndustryWeek's list of the Top 50 Manufacturers, it's also in second place -- after Western Digital (NYS: WDC) . That's a great reminder that while we tend to focus on big, familiar names, there are lots of exciting, lesser-known companies out there.

Western Digital may not be familiar to you, but there's a good chance you have one or more of its products in your home. Along with Seagate Technology (NAS: STX) , it rules the hard-drive manufacturing world, and its wares reside in millions of PCs around the world. As it has grown into a $7 billion player, it has made a lot of investors wealthier, averaging 23% annual stock-price growth over the past decade. Folks paying attention to what was inside those millions of PCs flying off shelves made some good money on Western Digital.

Stealth companiesSome are wary of Western Digital and Seagate now, though, worrying that PC sales will shrink in the face of tablets, and even hard-drive sales may be threatened, by cloud-based storage. For now, though, Western Digital remains at the top of the list of manufacturers, suggesting that its heyday isn't over yet.

Plenty of other stealth winners abound, if you just take some time to look for them. Looking into components is a great way to start. Remember the astonishing growth trajectory of Apple? Well, all of its popular devices have components, such as chips made by Cirrus Logic (NAS: CRUS) that manage power and sound and OmniVision Technologies (NAS: OVTI) image sensors. Apple is Cirrus' largest customer, in fact, which bodes well for Cirrus but can also be dangerous, should Apple falter. OmniVision has been doing well by developing technologies that have proved superior and more cost-effective than those of its competitors.

Lucrative facilitatorsAnother stealthy kind of company is the one that facilitates others' businesses. Consider natural gas. Many are bullish on it as an alternative to oil, and Chesapeake Energy (NYS: CHK) , a nearly $20 billion giant in natural gas exploration and production, is familiar to many. (Its CEO's excesses have kept some people away from it, though.)

But plenty of less-known companies are also positioned well to benefit from growth in natural gas. Clean Energy Fuels, for example, produces natural gas and operates some 200 fueling stations serving natural-gas-powered fleets. Cheniere Energy owns and operates receiving terminals and pipelines for natural gas.

If you're expecting manufacturing to take off once a global economic recovery is in full swing, you might think of big players such as Ford (NYS: F) , which has been preparing well by developing more fuel-efficient vehicles and investing heavily in research and development. But the auto industry can be tough. You should consider smaller, more obscure companies that serve manufacturing, such as copper and molybdenum producer Taseko Mines. Taseko stands to benefit from an increase in the price of copper as well as from infrastructure growth in developing nations such as China.